Turn of events
by StupidBolts
Summary: Slight AU based on the season finale, "Vengeance is mine". In which, Leo did not duck. Discontinued until further notice.
1. Epilogue

The moment it clicked in his mind that the blade of his katana was stuck through the lock of his cage, Leonardo wrenched himself free and tore through the Foot bots, darting towards the chain he'd noted attached to the floor by the Mutagen tank. Slicing through it, the turtle found himself being launched upwards towards Karai's cage. "Hold on, Karai!," he exclaimed, landing on the metal frame and grasping the chain it dangled from.

Hazel eyes looked up at him, swimming with relief, regret and gratitude, which she voiced when he pulled away the strip of tape from her lips. "Thanks!," she gasped, smiling up at him. He returned it, a sweet moment of triumph washing over him until he heard their Father yell his name.

"_Leonardo!_"

The grinding of metal struck his ears, Shredder leaping towards him like a hungry wolf, blades fangs bared. Leo snapped his head around, eyes wide, and his initial reaction was to duck.

_But the chain..._

Cold metal sank and slid through his semi-scaly flesh, producing a sickening blade-through-butter sensation. The sound of his heart pounding and blood rushing in his ears muffled the rip of his skin and throat, the pain coming too quickly to recall when it began, but his family's voices rang like church bells in the rush filling his skull. "_Leonardo!_," Splinter howled again, accompanied by the chorus of his four siblings, brothers _and_ sister.

"_Leo!_" The blades glided through his jugular, and before he could even attempt to gasp, his fingers slipped free of the chain.

"_Leo! **No!**_," Karai screamed, watching the blue clad turtle tumble. The resounding splash when his carapace hit the Mutagen sent ripples through the glowing ooze, a distorted stain of red drifting to the surface. Shredder landed on the opposite edge of the tank, the clang of his metal grieves causing further ripples in the chemical vat.

"Get her down!," the ninja commanded, pointing to Karai. The near severing of her cage made him realise that this plan was extremely flawed; he had a habit of underestimating Yoshi's sons. A Foot bot obeyed, and his adopted daughter's cage swung towards him, which he promptly grabbed. She screeched, clawed and beat at him as he pulled her from the cage, but he enveloped her in his strong arms, pinning her thinner appendages to her sides.

"_Leo!_," Karai shrieked again and again, even as Shredder leapt safely to the ground with her.

"He will have either drowned in the Mutagen, or his own blood," Tiger Claw purred in sadistic glee, placing his foot on Raphael's cage as the red turtle roared and cursed.

"_No!_," he cried, fighting with the bars of his cage. His brothers kicked and squirmed as well, tears streaking down their cheeks in horror, their sister making terrible screeches, until a bubbling sound rumbled from within the tank.

"At least... he _should_ have done...," the feline murmured, stepping away from the cages. Splinter's eyes widened and became hot with strained tears, as a green paw slammed against the glass of the tank. The sound of struggling and gurgling echoed from the vat, as if someone were indeed drowning, and then went silent. The screech of claws raking against glass made everyone flinch, accompanied by a resounding thud, as if a truck had been driven into it from within.

A large, four clawed hand burst from the glowing ooze and clamped onto the metal edge. It was far too large to belong to his son, yet he couldn't comprehend what else could have emerged from the tank.

Instead of Leonardo, a hulking, jagged creature hauled itself out of the Mutagen. It's jaw was long, arms built like brick walls with spikes of bone protruding from the elbows, and a shell the size of a small car adorned its back. Its claws buried themselves into the metal, and a long, sharp tail rose from the ooze. The creature stretched its jaw open so wide it didn't seem natural, rows and rows of stake like fangs lining its mouth and dripping with venom, Mutagen and blood. It leaned over the edge, making a wheezing, gasping roar of thunder that made the very warehouse shake at its foundations, the creature's thyroids, cartilage and vocal cords out on display in the two, gaping gashes in its throat.

Across its jade eyes, a streak of sky blue looked as though it was burned into his face.

Leonardo veered forward, then dropped over the side of the tank, landing with an earth-quaking thud on the floor below. Splinter watched him for a moment in stunned mortification, then ripped himself free of the binds and ropes, carving through Foot bots to his son's side in a matter of seconds. "Leonardo!," he panted, on the very edge of tears as he crouched beside the monstrosity. It was huge; larger than the mutant that Michaelangelo had named Leatherhead. He so wanted to believe that this _wasn't_ Leonardo, that this thing was _not_ his little boy. "Oh, my child..."

Sparking jade eyes snapped open, and a pearly green tail rattled and snatched at him. Splinter cried out in pain at the bone crushing strength of the appendage, gasping and heaving against it.

"Father!," Karai shouted. She struggled in Shredder's grip, before turning her head downwards and sinking her teeth into his bare bicep. The ninja howled and shoved her away, nursing the bite that now gushed with blood.

Karai spat out the chunk of human meat, and jumped up to free her new younger brothers.

She freed Raph first, who immediately sprang to save Splinter, while she released Donnie and Mikey. The red turtle scrambled up to the platform, skidding to a stop. Leo had no legs, but the long, muscled tail more than made up for it; even with most of it constricting their Sensei, he stood up straight to tower over most other mutants they had encountered.

Reptilian eyes locked onto the red clad turtle, and for a moment, Raph's blood ran cold with fear. Leonardo snarled, choosing to fling Splinter into his younger brother instead of attacking him, and focused his primal fury and confusion on the slew of Foot bots swarming the tank. His tail snapped like a whip, claws like Wakizashi blades. His two remaining brothers and their sister helped lower the number of bots, while Raph helped Splinter get to his feet.

On the other side of Stockman's lab, a dismantled Foot bot sparked and fizzled beside a pool of oil, spilling from a knocked over barrel. The liquid ignited, racing towards a collection of propane and oxygen tanks, immediately detonating them in fierce explosions. The delicate and volatile equipment around the warehouse began imploding, making Stockman buzz and wail in despair. "No! My lab!," he cried. The fly mutant was bashed out of the way as Splinter stampeded towards Shredder, standing a short way away in shaking, barely contained fury.

"_You_, Oroku Saki!," he roared, baring the sword he'd pulled from a Foot bot's head. "_You_ did this!" Shredder held his profusely bleed arm, getting light headed from the fast blood loss. As the rat boomed at him in his steely voice, all Oroku Saki could do was chuckle. The dizziness began to overtake him, eyes dancing from Yoshi to his monster-son, and he descended into a maddening cackle that shook his rib cage.

"Yes," he gasped with morbid glee. "I did. You took _my_ adopted daughter from me. I took _your_ adopted son from you." With a final bellow of anguish and rage, Splinter launched himself at Shredder, only for rubble to cave in from the ceiling and block him off.

"_No!_," he cried with a growl, fists trembling.

"Father!," Karai screamed. "We have to _go!_"

"Leave me!," Splinter snarled, whirling around on his daughter. She flinched, but a life time of witnessing the Shredder's fury left her feeling rather brave in the face of Yoshi's anger.

"I promise, Shredder _will_ suffer for what he's done to Leo!," she pleaded with him, grasping his wrist desperately. "But we have to leave and get my brother home!"

"Brother?" He turned his eyes up to the turtle-snake abomination Karai claimed was her sibling, and felt his heart shatter for what felt like the millionth time in his life. "I shall avenge you, my son...," he breathed, then grasped Karai's hand and the two ran towards the remaining turtles.

"We've gotta get out of here!," a frantic Donnie shouted over the hiss of flames and smoke. Raph whipped around to face the mutagen tank again, where Leonardo had taken perch at the top, shaking the collapsing building with his stormy roar.

"Not without Leo!," he retorted firmly. Splinter silently agreed, stepping towards the vat.

"Leonardo, you must listen to me!," he called to him. "We _must_ go!" Catching the beast's attention seemed to be a mistake; jade eyes snapped to the rat, and his natural instinct to eat vermin rose its ugly head. He leapt from the tank and gripped Yoshi in his tail once again, crushing with an ungodly force. Splinter choked and struggled, but refused to produce the tanto blade in his sleeve. "My son... _please_."

Leonardo froze, eyes widening as he stared down at the rat, leaning back in confusion. His jaw fell open as if to speak, but the only sounds produced were broken and near illegible. "... _Arr... err..._" Splinter looked up at him pleadingly as he forced back the burning tears, recalling a time where he gently held Leonardo in strong arms, cradling and lulling him to sleep after a nightmare.

The beast hissed viciously, dropping his Father and shooting past him, veering up in front of Raph and spewing venom into his eyes, ensuring the others wouldn't follow him out of the warehouse. His brother screamed and fell to the floor and Leonardo slithered like a bullet from a gun into the smoke and flames, disappearing from sight, though heard Karai call out to him. "Wait! _Don't go!_"

* * *

It was raining outside. Near monsoonal, she concluded as an after thought, scaling a billboard for a higher vantage point. The effort was in vain; Leo was no where in sight. She made a pained sigh of defeat, eyes drifting down to the roof top, before she turned and jumped back to her family.

Donnie was sitting with Raph, washing Leo's venom from his luminescent green eyes, though the hot head was rancid and spitting curses at his younger brother, and no one could blame him. She wandered past them, glancing mournfully to the red clad turtle, and stopped a few feet short of their Father.

She took a shaky breath, shaking and hanging her head in shame with tears building in her eyes. "This is all my fault," Karai breathed. "I should have listened to him in the tunnels... I'm so sorry, _Tousan_..." Splinter didn't respond immediately, making her aching heart skip a terrified beat; he stood statue still, staring at the billowing smoke and flickering pyre of Stockman's lab, rain drops running over his slick fur and kimono. "_Tousan...?_"

His shoulders slightly twitched, though for what reason, she couldn't say. With a voice as dark and cold as a grave yard, he whispered, "We should go home, my children."

Her brothers began following their Father as he trudged towards the fire escape of the building, all of them looking around at one another haplessly. "You can make a retro-mutagen for _Niichan_, right?," Mikey whimpered to Donnie. The taller turtle wouldn't look his brother in the eye, walking along with his gaze on the stone roof.

"I don't know, Mikey... I hope so."

* * *

**_Hail to the princess, baby!_**


	2. Faces behind the glass

**I'd like to apologise for any mistranslations in this fic; I don't actually speak Japanese, if that wasn't painfully obvious, so Google translate was used. Thank you.**

* * *

Leo wheezed and grasped at his throat; venom _burned_. His primal instinct to reach safety began to fade along with his confusion and panic, and he began assessing the situation. He'd reached Karai in the cage – yes, he remembered her pretty amber eyes looking up at him – and he'd removed the tape over her mouth – that's right, her lipstick had been smeared – and he'd heard the unthinkable.

"_Thanks."_

What an odd thought; Karai _thanked_ him. He'd felt a moment of triumph and pride that, for some reason, didn't last.

_What happened after...?_

He recalled his Father's panic, the call of his own name – familiar feeling, _tousan_ is calling – Karai's eyes sparked with fear as he turned his head, the only thing in his line of sight were a pair of claw-like blades arching towards him, and then...

Leonardo choked, gagged and coughed, letting out a despairing howl and ripping down a billboard. His eyes burned as deeply as his throat, bitter tears dripping over his cheeks. A puddle caught his attention, so he leaned over it to stare at his reflection. He might have screamed at the abomination with jade eyes, if he didn't know who it was that he was looking at.

_Oh god, look what he's done to me..._

The monster-mutant howled painfully into the rain, then caved in on itself, pressing its face into the puddle. The water sloshed against his hot cheeks, splashing and hissing as more rain fell.

Focus on the water – rain had always always been comforting to him – calm down, _think_. There must be a solution. How did things normally get solved?

"_One sprits of this and you'll be as good as new, mister O'Niel!"_

Donnie. Clever little brother that wasn't so little anymore – focus on that, on the thought of your amazing brother – he'd created a retro-mutagen already, but it took time to make, he'd said. Leo's heart gradually began to slow, having been pounding mercilessly against his chest. He took a deep, deep breath – amazing brother, yes, think of your _family_ – adrenaline faded from his blood, and he closed his eyes – amazing brother, funny brother, beautiful brother – his skin began to prickle, and his joints hummed like hot steel – warm Father, strong sister and sad sister – his legs shivered in the cold rain, but it was very much welcomed...

Wait, _legs?_

He snapped upright again, staring back into the puddle. Jade eyes still peered back at him, but a familiar face held them, though it was somewhat scalier. His blue mask had melted into his flesh, looking like a scar around his eyes. Fangs still poked from between his lips and his armoured plastron had been replaced with smooth belly scales, seemingly fading in from under his chin and leading down his front, disappearing between his legs. He looked around, however, to find that his horrendous tail was still very much there. It had simply risen to protrude awkwardly from his lower back, slithering as though it had a mind of its own.

_This will take some getting used to._

He looked back down at the puddle and lifted his chin a little; the gash was still there, the insides of his throat still out on display, his tongue twitching as he gulped. Leo shuddered and opened his mouth. _"That's revolting!,"_ he'd meant to say, but all that came from his lips was a soft wheezing sound. He froze, looking straight ahead. _"Hello?,"_ he tried again. _"Voice, are you there?"_ Nothing but the wheezing would come out, so he slapped his hands over his mouth to prevent it, tears building up in his eyes again.

_He's taken my voice from me..._

One hand slid down to his neck, covering the hole as he squeezed his eyes shut, falling back to sit on his knees and bow his head close to the floor, shuddering but forcing back the tears.

_Shredder... Oroku Saki..._

But then, a memory surfaced at the forefront of his mind – pain and shock did terrible things to a person's memory – of the _chain_. Karai's cage dangled above the vat of mutagen by a pathetic little chain, which would have been so easily severed with the Shredder's careless swiping at Leo, and if he'd moved out of the way...

_This could have been Karai._

Leo opened his eyes, reptilian pupils thinning dangerously as he got to his feet, standing in the rain with determination. As mortified as he was – good god, he couldn't _speak_ – his sister was safe. She will have escaped with their family, away from the Shredder and away from Leo, and she was _safe_. Because he hadn't moved. Pride swelled in his chest; perhaps it was not quite how he'd originally intended to rescue her, but he'd saved her nonetheless. The sacrifice was necessary and worth it.

Leonardo turned away from the puddle, long and muscular tail dragging through the water as he involuntarily let out a sudden, _"Hissssss!"_

His eyes bulged; so he _could_ make some kind of sound, creepy as it was. He would have rejoiced, if the noise didn't trigger a dull, animalistic memory in his mind.

_Raphael's scream of pain as venom was spat into his Peridot eyes._

"_Raph!,"_ he'd meant to cry, grasping his head in sudden horror. He'd hurt Raph; he'd potentially _blinded_ his beautiful brother. _"No!"_ His knees met the ground again, hands moving to cradle his face as he silently wailed into his palms. More memories arose; how his tail had coiled around Master Splinter and squeezed, how his stomach had rumbled with anticipation – he'd intended to _eat_ his father – and it made his guts churn. All of a sudden, everything he'd eaten in the past twenty four hours poured from his mouth and onto the roof top.

He had wanted to _eat_ his Father.

Leo panted heavily, wiping his lips but being mindful of his fangs. His eyes sparked furiously – this was _Shredder's_ fault – his shoulders trembled and his tail quivered, convulsing horribly – but now the beast was his responsibility, and he had to learn to control it – his muscles burned and bulged, and his legs vanished into his flesh, adding to the tail's length and raising him high into the air.

_But control can wait until Oroku Saki lies in a pool of his own blood._

The monstrosity let out a mighty roar, blending with the thunder booming overhead.

.

The turnstiles creaked slowly as each Hamato lumbered into the lair. Karai looked over her new home, then back to the entrance. Gates had never looked so accusing.

"Guys!," April cheered, bounding down the steps from the dojo. "There you are! We were wondering where you'd gotten to!" Casey followed close behind her, hands stuffed in his pockets. "Where'd you all go?" The red head looked around at her family, observing their depressed expressions, and her smile suddenly fell. She then realised that someone was missing. "... Guys, where's Leo?"

Raph dragged himself down into the pit, dropping onto the couch and holding his head in his hands. Mikey and Donnie glanced at each other, then the taller turtle wrapped his arm around his brother's shoulders. Karai stood off to the side, head cast down at the floor but eyes closed. Master Splinter took a deep breath, then replied. "He was... he is... alive. Alive, but no longer with us, my child." April's eyes widened, and Casey came closer, looking equally concerned.

"Wh... what, I don't...," she stammered, eyes flitting about desperately to the others.

"Shredder gutted him, and tossed him into a vat of freaky Mutagen," Raph suddenly barked, getting to his feet with a stamp. "And when he came out, he was this... this... _thing!_," he exclaimed, throwing his arms out as he turned to face the two humans. "Some kind of turtle-snake _monster-mutant_, and began tearing bots to bits, tried to _eat_ sensei!" April clamped her hands over her mouth, knees knocking together as she trembled.

"N-no!," she gasped, tears beginning to fall, eye liner streaking down her cheeks. "No, it can't be! You're lying!," the red head cried, throwing her head forward and pressing her fists to her chest. Casey tensed, watching his best friend shake with that dangerous rage of his, intensified to levels he didn't even want to guess at.

"You think _I'd_ lie about Leo?!"

"I... I...," she stammered, arms dropping limply at her sides. "L-Leo would never-! No, not Leo!," April screamed, whipping around to face the other human. The dark haired boy readily opened his arms and gathered the sobbing girl into a bear hug against his chest, holding her tight and rocking her from side to side.

"_Yes Leo_," Raph snarled. His bright eyes darted to Karai, seething with bitter anger and stomping towards her. The dark haired girl stood her ground, lifting her head and staring him straight in the eye until they were almost toe to toe. "And it's all _your fault, princess!_"

"Raphael!," Splinter bellowed far louder that usual, startling the four remaining children, but Raph wouldn't be perturbed.

"It's _her_ fault sensei, and you _know_ it. I know she's your daughter, I _know_ you love her. But can you seriously turn your back on _him?_," he shouted, gesturing into space as if Leo were standing there. "I _know_ that she's your flesh and blood, but you _raised_ us! You're our Father too! If she'd _listened_ to Leo, if she hadn't gone after Shredder alone like a spoilt moron, _none_ of this would have happened!" He whipped around again, and Karai noted how blood shot his eyes were. Whether it was from the venom or restrained tears, she wasn't entirely sure. "My brother is a dangerous, insane monster, and it's _your _fault!," he screamed, raising a fist to punch her dead in the face.

"You're completely right." The room was silent, everyone staring at Karai, even Raph's eyes going wide with surprise. "It is my fault. I should have listened to Leo, and I regret not doing so. But I can't say or do anything to change what I've done, Raphael. I can't jump back in time and stop myself from knocking him out and going off alone. And I can't say or do anything that could possibly make up for what Shredder and I have both done to your... _our_ brother." She took a step back and sank to her knees in a bow before him, hands planted on the floor and head hung. "If hitting me will appease you, then do so as many times as you like. But it won't help Leo. But I promise you..." Her head snapped up, looking him dead in the eye. "I _will_ find him, and I _will_ bring him home. With or without anyone else's help." Raph stood statue still, fist still raised, hyperventilating slightly, staring at her as if she was some kind of horrifying creature. But his arm slowly lowered, keeping eye contact, and he gradually calmed his breathing.

"What the hell are you saying?," he murmured. "_With or without_, as if we aren't willing to search the entire planet for him."

Donnie managed the weakest of smiles as a form of agreement, but it dropped almost immediately. Mikey sniffled, turning into his brother and wrapping his arms around him. The genius swayed them both to and fro. "Shh, Mikey. Everything's going to be alright," he whispered too quietly for anyone else to hear.

"How do you know?," his little brother whimpered wetly.

"Because I know everything, remember?," Don feebly joked. Mikey made a slight snort, but clearly wasn't amused. The purple clad turtle took a shaky inhale, then pressed a kiss to his forehead. "You wanna sleep in my room tonight?" Mike nodded slightly, and Donnie rubbed his back and continued cradling him.

Silent as a mouse, ironically, Splinter slipped away from his children. He knew better; knew he should calm April and Michaelangelo, assure Donatello and Casey, praise Raphael and Miwa for their behaviour. But his eyes burned so fiercely, he feared they'd catch fire and his tears would fall, and god knows he couldn't bear for the children to see their strong, steely master in that state. So into the dojo his snuck, across the tatami mats, snatching up the photo of his family and through the screen doors, closing them behind him. He held the photo of his wife, baby and past self to his chest, trembling. With a sharp breath, he turned, marching to the far side of his room and opening a drawer, retrieving a wooden box buried beneath the spare blankets they kept for the sewer winters.

Placing the photo against his futon, he sat with his box and undid the latch, slowly opening the lid. He looked down at the collection of _things_ from years gone by; Tang Shen's obi that he'd retrieved from his burning home, the wax crayon drawings Michaelangelo had scribbled as a tot, the wire figures Donatello had made for him as a child, the shiny objects Raphael had scavenged during his non-permitted adventures through the tunnels.

His rodent fingers delved into the box, pulling out a fat, scruffy book, and a wooden block.

He admired the wood carving Leonardo had pained himself over for weeks on end; his eldest son had an artistic talent that could have lead him to great things in the world above. It was a beautiful visual story of a samurai going off to war, leaving his lover beneath a cherry blossom tree and a new moon. She waits for him there for days and days, until they are finally reunited beneath a full moon. He smiled sadly at it, a tear threatening to roll down his cheek. He wiped it away with his wrist, setting the carving down beside the framed family portrait, and opened the album.

Early in his sons' lives, he'd found an old camera laying in a dumpster on the surface while searching for food. He'd only noticed Donatello's genius when his vanished with the device for several hours, then returned running up to him and shouting, _"Smile, daddy!"_ He looked at the photo of his surprised expression, chuckling wetly at the silly picture. He turned the plastic-covered pages, over the photos over his boys playing, training and eating. He lingered on a particularly funny one where Leo was lifting a screaming Mikey into the bath tub. And one of Leo bandaging Raph's damaged hand. And Leo carrying a sleeping Donnie to his room. And Leo training his brothers.

He found the photo he was looking for and slid it out of the album. He picked up his framed photo and opened it, placing the other photo over the image of himself beside Tang Shen and Miwa.

Leo's face beamed behind the glass, holding a cup of green tea, his little boy simply smiling warmly at Raph, who had taken the very sweet photo. He traced his finger tips over the faces of his lost loved ones, though paused on Miwa, letting a slight twinge of relief into his heart._ She_ was safe, thanks to her brother grinning beside her mother.

He clutched the frame to his chest, squeezing his eyes shut and clenching his sharp teeth. "Leonardo, my child... _Mamonaku watashitachi ni modotte kuru__._"

* * *

**_Hail to the princess, baby!_**


End file.
